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Wha Gw F2d2 0 As Z2 Eth FirmwareOperating system · Pepperl Fuchs

CVE-2021-34559

MEDIUM · 5.3 CVSS v3.1 Published 2021-08-31
Fix available
A fix is available. Upgrade to after 3.0.8 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In PEPPERL+FUCHS WirelessHART-Gateway <= 3.0.8 a vulnerability may allow remote attackers to rewrite links and URLs in cached pages to arbitrary strings.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a cache poisoning vulnerability in PEPPERL+FUCHS WirelessHART-Gateway web interface (version <= 3.0.8). Remote attackers can manipulate cached pages to rewrite embedded URLs and links to arbitrary strings, potentially redirecting authenticated users to malicious sites through the gateway's cached web content.

MitigationApply the vendor patch if available; otherwise, consider disabling caching for the gateway's web interface or implementing strict Content Security Policy headers to mitigate URL manipulation in cached responses.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Wha Gw F2d2 0 As Z2 Eth FirmwareOperating system
Affected:<= 3.0.8
Wha Gw F2d2 0 As Z2 Eth.eip FirmwareOperating system
Affected:<= 3.0.8

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the device model
    Access the gateway's web interface or check the device labeling/sticker to confirm it is a Pepperl Fuchs WirelessHART Gateway (F2d2 0 As Z2 Eth or F2d2 0 As Z2 Eth.eip variant)
    Affected if The device is not a Pepperl Fuchs WirelessHART Gateway - this CVE does not apply
  2. Check the installed firmware version
    Log into the gateway's web interface and navigate to the system information or firmware version page, or use the device's CLI if available to query the firmware version
    Affected if The firmware version is 3.0.8 or lower - this indicates an affected version
  3. Confirm the web interface is enabled
    Attempt to access the gateway via HTTP/HTTPS on the expected web port (typically 80/443 or vendor-specified port). If a login page or web UI loads, the web interface is active
    Affected if The web interface is disabled and not accessible, the attack surface is reduced but the vulnerability may still exist in the firmware
  4. Inspect HTTP response caching headers
    Use a browser developer tool or curl -I to fetch a page from the gateway and examine Cache-Control, Expires, and ETag headers in the HTTP response
    Affected if Caching headers are present and indicate responses are being cached (e.g., Cache-Control: public/max-age > 0), which is required for the cache poisoning attack to function
  5. Check for URL manipulation in cached responses
    Make an authenticated request to the gateway, capture the response, then make a second request and compare the URLs/links embedded in the HTML to see if they can be altered or are consistent
    Affected if Embedded URLs in cached pages can be modified or differ between requests, indicating active cache poisoning

A user is affected if the device is a Pepperl Fuchs WirelessHART Gateway running firmware version 3.0.8 or lower with the web interface enabled and caching active.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 3.0.8
Interim mitigation

Apply the vendor patch if available; otherwise, consider disabling caching for the gateway's web interface or implementing strict Content Security Policy headers to mitigate URL manipulation in cached responses.

Recommended fix Moderate confidence

Firmware version > 3.0.8 (contact vendor for specific fixed release)

  1. 1. Identify the exact model number of the PEPPERL+FUCHS WirelessHART-Gateway device in your environment
  2. 2. Navigate to the official PEPPERL+FUCHS support portal or contact their technical support directly to obtain the latest firmware version
  3. 3. Download the firmware file from an official source (such as cert.vde.com or pepperl-fuchs.com)
  4. 4. Review the firmware upgrade instructions in the product manual
  5. 5. Backup the current device configuration before performing the upgrade
  6. 6. Upload and apply the new firmware to the device via the management interface
  7. 7. After upgrade, verify the device is functioning correctly and the vulnerability is resolved
Caveat Review release notes for any configuration or compatibility changes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Wha Gw F2d2 0 As Z2 Eth Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-34559 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data